Sorting and selecting apparatus



Aug. 25, 1964 J. B. POWERS SORTING AND SELECTING APPARATUS 3 Sheets-Sheet 1 Filed March 10, 1958 75 Confro/ Eli Il a "a "a f F 9 HT f m z m i 7 M. H 6 WM a 2 H 21$? 1 w H m Q m m a m D i m m o w a. HQ H Mum mumm wbwb EH Wm /l/ w /l4 of M! of INVENTOR. Jamv .5. Pea/25 BY i/. r.

FIG'3 Aug. 25, 1964 J- B. POWERS 3,145,844

SORTING AND SELECTING APPARATUS Filed March 10, 1958 I 3 Sheets-Sheet 3 M9 9/4? Mi Z09 INVENTOR.

Jay/v 3, P041525 2/5 Irrazvir! United States Patent Office 3,145,844 Patented Aug. 25, 1964 3,145,844 SORTING AND SELECTING APPARATUS John B. Powers, Los Angeles, Calif., assignor to The Regents of the University of California, Berkeley, Calif., a corporation of California Filed Mar. 10, 1958, Ser. No. 720,128 19 Claims. (Cl. 2(l9-74) This invention relates to apparatus for selecting and sorting articles into groups having substantially uniform characteristics, such as uniformity of color, shape, size, weight or the like.

In the problem of sorting and identifying articles to distinguish one from the other, the objective is usually achieved by making a comparison between individual articles which are to be selectively arranged in like characteristic groups. In so doing it is important that at some point in the operation the articles be arranged in file formation, in which formation the selection occurs. Selective removal of articles from the file to allocate those of like characteristics to like groups must be provided in accordance with an appropriate form of control. Generally speaking, it has, in the past, been customary where articles are sorted in file formation, to have the articles move in sequence along a selected path. To remove the articles from the selected path it has been necessary to provide a component of acceleration effective in such direction that there is a force component acting in a path normal to the direction of file movement.

Where rapid sorting is to be effected it is apparent that the force required to be exerted on the articles moving in the file is dependent upon the time over which the displacing force can be applied to the article. Thus, if the displacing force is applied from a single point only and rapid sorting is to be effected, the force will have to be considerably greater than if it can be applied for a longer period of time to become effective for a longer distance along the file.

According to the present invention, which for explanation purposes will be set forth particularly in the form where it is applied to the sorting of fruit, which is easily subject to damage and bruises if force is applied thereto, this desired result is achieved in a new manner. Principle-wise the invention remains unchanged regardless of its field of use, but since it finds special application in the fruit industry, where it makes possible a sorting operation wherein there is a complete avoidance of high acceleration article removal force, so that there is almost a complete unlikelihood of fruit damage, it will be described in this field. With this broad principle in mind it will be seen that the present invention is so constituted that the articles to be sorted are subjected to a continuous controlled acceleration which will not damage them and, then, by removing the accelerating force from individual articles in the file, the various articles are separated one from another with force removal rather than force application.

Illustratively, according to the present invention the sorting mechanism comprises, generally speaking, a device or member, capable of being rotated about a central axis and arranged so as to hold the articles tobe selected in removable fashion when they are sequentially positioned about the periphery. For selection, the articles to be sorted are directed toward the periphery of the rotatable member, which is preferably of frusto-conical form, from the central region thereof so that the articles to be sorted first contact the rotary member in a region where the member is moving at a very low velocity. Then, from the point of first contact with the rotary member, the articles are transferred in position from the central or inner region progressively out toward the periphery in controlled centrifugal action caused to become effective in a generally stepped fashion.

When the articles reach the periphery of the rotatable device they are held thereon in releasable fashion and there subjected to a constant force acting in the direction of the center of rotation or drive axis of the member. A removal of this constant force at a selected time makes it possible to remove the articles from the file. The force for holding the several articles to the rotary member may be applied by holding gates at the periphery of the frustoconical member and may be removed, forinstance, by the selective opening of the gates. With each gate opening the article held therein is released and freed from the effect of any holding force acting upon it so that it can continue in its direction of movement along a path tangential to the rotary element with the point of tangency being at the point of article release. The article removal will occur at its start at the peripheral velocity of the moving element at the time the article is released. After the article has left the rotary element it is subjected only to the force of gravity (neglecting forces due to wind resistance, air friction and the like) and thus it keeps moving in the direction in which it was traveling at the time of release, except for the effect of gravity thereon.

When the articles to be sorted are held at the periphery of the rotary element prior to their release they are subjected to a holding force acting in the direction of the center of rotation of the member, which force holds the article in their position. It is important that this holding force shall be restricted to a magnitude such that its effect on the article itself will not be damaging. When the force is removed, as by opening a sorting gate under a suitable control, the article is no longer subjected to any force (other than that of gravity, wind resistance, air friction, and the like, as above stated). The control of the angular position at which the force is removed is established by a suitable exploratory means provided to observe each article in sequence following its positioning at the periphery of the rotary element. Then, depending upon the results of the observation, the articles can be selectively removed after the rotary element turns through selectable arcs removed from the exploring mechanism.

As each article is removed from the periphery of the frusto-conically shaped dish upon opening the gates in which it has been located and held, its discharge path is initially tangential to the dish periphery. Then, while the article is subjected to the effects of the force of gravity and air friction, it is directed into a collecting bin or the equivalent. Suitable provisions are taken to prevent damage to the fruit or other articles by bruising but, since these means and devices of themselves constitute no specific part of this invention, they are not discussed other than by merely acknowledging the need of providing such components with a device of the character here to be described and with the recognition that in practice such devices are almost essential.

From the foregoing brief description of the functioning of the apparatus it will become apparent that one of the primary objects of the invention is that of providing for selecting or sorting articles arranged in single file array by identifying the objects in accordance with their color, shape, size, weight or some other characteristic and then removing the articles one by one from the file by removing the force which holds the articles in the single file alignment. The mere removal of the force effective in the selected region of the file, as made possible with careful control, precludes having to apply any other displacing force which would otherwise necessarily become effective in the selection and which, if applied, might lead to damage of the selected article.

A further object of the invention is that of providing a selecting mechanism for segregating articles into groups of substantially uniform characteristics through utilization of a selecting mechanism into which memory is introduced. This memory provides that within any selected unit time period (which can be measured or determined, as desired) the removal of articles from a single file array can be randomly shifted under appropriate control indicative of the different classifications so that articles having certain like classification can be removed from a single file array to be segregated with respect to articles having one or more different classifications, with the selections actually occurring at different instants within the unit time period.

Still another object of the invention is to provide selection or sorting apparatus wherein each of a plurality of articles moving through the apparatus in file arrangement may be individually examined and viewed sequentially from all sides, as well as from above and below and front and back, so that the integrated effect registered on the exploring medium may represent the average characteristic of each complete article. This characteristic, illustratively may be indicative of the reflectance of the object to light at two rapidly switched substantially monochromatic spectral ranges with the resultant measured output then being utilized through appropriate memory devices to control the discharge or removal of the articles from the single file array in a fashion such that articles of like characteristics are discharged from substantially the same relative position along the file.

Other objects of the invention are those of providing for the development of signal indications representative of the average light reflectance of each object to be sorted when each object is rapidly and sequentially illuminated from substantially all directions with light of substantially monochromatic wave lengths selected at different regions of the visible spectrum. The produced signal indications are utilized to control removal of the articles from the single file array according to a pattern whereby articles of substantially like selected characteristics are always removed from the file at substantially the same point in the single file movement. In this way the removed articles segregate themselves into groups of which each individual group includes articles having a like characteristic, although the different groups each are formed from articles of characteristics such that the groups all differ.

Still a further object of the invention is to provide for holding a multiplicity of articles in single file array and removing the articles from the array one by one with the removal being elfected by removal of the holding force by which each article is held in the single file array. In this case the removal of the holding force insures that the object will not be damaged due to any dislacing force being applied to remove it from the file. The removal of the force is caused to occur at points such that the articles leave the single file array at several selected points and thereby collect in groups which each include only like characteristic objects, despite the fact the characteristics of each group are different from each other group.

A further object of the invention is to provide for the production of signals indicative of the index of the variation of reflectance characteristics of each object of a plurality moving in single file array with respect to an examining point, and the utilization of the product indications to bring about selective removal of the articles from the single file array in order to segregate articles of one characteristic from articles of other characteristics.

Other objects of the invention are those of providing sorting and selecting apparatus which is substantially foolproof in its operation; apparatus which utilizes both electrical and magnetic etfects controllably coordinated one with the other to effect the article sorting and selection; as well as to provide apparatus which functions rapidly or at a rate higher than that normally manually achievable, while, at the same time, being capable of achieving the sorting and selecting operation both more accurately and cheaper than would be possible from an equivalent manual selection, it being clear that the electronic selection is free from the color sensitivity which often varies between individuals working on a sorting project.

Still further objects and advantages of the invention will become apparent to those skilled in the art to which it is related when the following description and the hereinafter appended claims are read in conjunction with the accompanying drawings wherein:

FIG. 1 is a partly broken away sectional elevation of a sorting device adapted to move objects from a receiving point into a single file array, showing holding gates for maintaining the article position and for releasing the article under appropriate control following article inspection and exploration;

FIG. 2 is a schematic plan view of the apparatus of FIG. I particularly adapted to show the article discharge at selected points on the periphery of an article carrying dish rotating at substantially fixed velocity;

FIG. 3 is a schematic view partly broken away to represent an expansion of the cam tracks controlling the operation of the shuffle mechanism for moving articles individually and one at a time from a central region of the frusto-conical sorting wheel out to the dish periphery, the control being shown in the operating cycle, as compared to an assumed and illustrative three-shufile showing of FIG. 1, with the outermost shuttle control represented by the upper cam track, the intermediate shuffle control being represented by the central cam track, and the innermost control being represented by the lower cam track, each rise being shown in general relative location based upon a device rotation of 360 and the rise positions following gate openings;

FIG. 4 is a diagrammatic view schematically to represent the discharge sequence of articles of different color classifications with respect to each other as the articles are held at the periphery of a rotary element of the general type of FIG. 1 and discharged at different points during the rotation of the frusto-conical dish, with the points of discharge being selected in accordance with different article characteristics;

FIG. 5 is a schematic view to represent a typical control circuit including the electronic scanning or exploring apparatus and the magnetically operated gate controls with the control drum secured to the driving axis of the frusto-conical article support being shown sectionally and in part with the magnets extending outwardly therefrom being conventionally indicated;

FIG. 6 is a development broken away and sectionalized at various parts to represent the spacing of the magnetic controls for effecting article discharge at different peripheral points and for removing undischarged articles, prior to reloading, at a selected point in the operating cycle and once during each revolution of the frusto-conical article-holdin g dish;

FIG. 7 is a schematic illustration partly broken away to show the manner by which the magnetic circuits are established; and,

FIG. 8 is a partial plan view taken along the line 88 of FIG. 1 and is to show the latching mechanism of FIG. 1 in plan.

Referring now to the drawings for a further understanding of the invention and first to FIG. 1, thereof, the invention will be described in one of its embodiments as being related to the identification and sorting of fruit, which, for purposes of illustration, may be considered as lemons. Illustratively, the fruit may fall into various classifications which are well recognized in the art and which are known as dark green, light green, silver and yellow. The invention, as it herein will be described, provides for segregating each characteristic of fruit and then collecting each segregated fruit piece by removing the fruit from a single file array at selected points in the file, with the determination of the removal point being in accordance with the particular classification into which division is to be made.

amass;

The single file array, as herein to be described, will be a single file arrangement of individual fruit pieces about the periphery of a dish-shaped or frusto-conical member Where the fruit pieces are individually held in suitable, peripherally positioned, gates. As the gates are opened one by one to permit the fruit held thereby to leave the dish periphery coincidentally with the removal of the holding force provided by the gate, the separate pieces move away from the carrier along a path tangential thereto.

The normal operation of the apparatus is such that a maximum length of the single file path is less than one circumference of the periphery of the frusto-conical dish with it being recognized that path length may be but a minor fraction of the dish circumference. Illustratively, assuming that the fruit pieces are moved to the dish periphery, the exploration of the individual pieces for the purpose of analyzing each to determine its selected characteristics, say color characteristics, may occur following a very short arcuate path of the single file array following gate-loading. Then, assuming the articles have one selected characteristic, such for instance, as that of being dark green (in the case of the assumed lemons), the holding force exerted upon the fruit piece may be removed substantially concurrently with the exploration. This removal of the holding force then permits the supported article to leave the wheel or dish at once, as will later be explained in greater detail, and means that this particular region of the single file gate arrangement is void of any held fruit until reloading occurs following substantially a complete rotation of the frusto-conical dish. For another characteristic of the assumed supported fruit piece, the discharge point may occur following a longer movement along the arcuate path corresponding to the dish circumference so that the period between discharge and reloading will be shorter. As the apparatus is designed to function and, as it will herein be explained, all supported and located fruit pieces are discharged prior to the reloading point, regardless of the article characteristics in order that each point on the file may be conditioned to receive a new or different article for analysis prior to each passage of the selected point before the exploring means.

So considered, various fruit pieces 11 to be sorted are supplied by way of the chute or duct 13 to come to rest upon a substantially fiat section 15 of a frusto-conical fruitsupporting dish, generally represented at 17. For convenience of illustration the fruit pieces 11 are shown as round, although it is only schematic and adequate to present the operating principle only. The dish 17 is supported for rotation about a vertical axis, shown in the form of a supporting spindle 19, appropriately secured and locked to the flattened section 15 by the conventionally represented support base 21, which is keyed to the spindle 19 to rotate with it.

Any appropriate form of drive may be provided for turning the spindle but by way of illustration one suitable form comprises the motor, conventionally represented at 23, secured to the rigid support frame bracket 25. The dish 17 is driven from the motor 23 through the illustrated chain drive 27 (or equivalent drive), wrapped about the driving sprocket 29, keyed to the rotating motor armature. The driven sprocket 31 is keyed to the support spindle 19.

Purely from a schematic arrangement, the shaft is suitably journalled in the conventionally represented bearings 33 and 35 carried at the upper and lower ends of frame support brackets 37 and 39. With the drive operating in the direction indicated by the arrows, the frusto-conical dish will rotate in a counter-clockwise direction (see for instance FIG. 2).

Considering now in further detail the frusto-conieal dish 17, the substantially central flat section 15 merges with the generally conical shaped outer wall, conventionally represented at 41 (see for instance FIG. 2), which outer wall comprises a combination of lifting elements which are fiat sections and the fixed vertical fruit locating vanes 43, 45, and 47. The vanes are circularly arranged and extend at approximately the indicated height, relative to the conventionally shown articles 11, about the underside of the dish wall effectively forming a closer member therefor. These fruit locating vanes have depending therefrom bearing members 49, 51, and 53, respectively, which are adapted to locate the flat sections.

The upper portion of each bearing member is flattened to provide a seat for the lifting elements 55 in connection with the inner bearing, 57 in connection with the central bearing, and 59 in connection with the outer bearing. The upper surface of each lifting element extends in a plane substantially parallel to the plane of the central flat section 15. A lift rod 61 is secured to each lifting element and terminates in a forked or bifurcated end which supports a rotary cam follower 63, adapted to roll on one of the cam tracks, such as 65, for the inner lifting member, 67 for the central lifting member, and 69 for the outer lifting member. Each of the cam tracks 65, 67, and 69 is circular and extends at the radius indicated by the showing of FIG. 1 in a circular path about the axis of rotation of the dish and is supported at appropriately spaced points on radial spoke members 71, extending between the outer rim support 73 and the upper support bracket 37. The followers 63 are forced against the earns 65, 67 and 69 by springs 74 which are secured to the rods 61 and compress against the bearing members 49, 51, and 53, as shown.

The cam tracks 65, 67, and 69 are generally flat for substantially the entire circular periphery with the exception of one region of relatively short arcuate extent whereat the track is elevated and adapted to cause the cam follower 63 to rise against the force of springs 74 from the plane of the major portion of the track. As each cam follower is lifted in sequence it also moves its attached lift rod 61 upwardly to lift the therewith associated lifting element 55, 57, or 59, as the case may be.

Referring to FIG. 3 of the drawings for a moment, a development in profile of the several cam tracks has been shown with acam track length of 360, representing one complete circumferential length of the follower path for each drum rotation. Each of the cam tracks 65. 67, and 69 has been plotted to show the relative point of rise of the cam surface with respect to one complete revolution but without regard to the fact that the outer path is longer than the inner path, and so on. In the illustrated example, it may be assumed that the position of 0 (and thus also 360) represents the point of article exploration or identification and that the point of rise from the common fixed plane in each cam track occurs at an arcuate distance following the point of. exploration which is beyond that point where all articles finally reaching the periphery of the dish-shaped member 17 (as will later be described) have been discharged.

The positioning of the rise portion is not critical with the exception of the limiting fact that the cam tracks must, in the illustrated form, all rise to the maximum height in sequence with the outer track first and inner track last, and each operation must be complete before the next starts and all must be completed prior to the time the dish rotates to the load position, which event, of course, occurs prior to the exploring position. This is to insure maintaining the wheel periphery gates in a loaded or full status to the fullest extent possible and also to insure that a vacant lift region is providing for permitting the fruit pieces to move progressively outwardly toward the disk periphery.

So considered, it is now appropriate to refer further to the showing of FIG. 1 and to take note of the fact that the article 11, shown immediately above and resting upon the lifting element 55, is also bearing against the locating vane 43. Similarly, the conventionally represented fruit piece 11, resting upon the lifting element 57, abuts the locating vane 45 and is held adjacent thereto. Likewise, the fruit piece 11 which rests upon the lifting element 59, also is forced against the locating vane 47. Lastly, the fruit element 11, shown at approximately the peripheral edge of the frusto-conical dish 17, is held by the gate element 75 from beneath and is guided from above by the conventionally represented guide tracks 77. The guide tracks 77 are preferably in the nature of a pair of adjacent Wires (see FIG. 2) which extend circularly with respect to the periphery of the dish and are supported by spaced brackets 79 which, preferably, are secured to the outermost vertical fruit locating vanes 47.

With the gates 75 in the indicated position of FIG. 1, which will be assumed as the closed position, fruit pieces 11 which have moved up the shuffle structure of the generally conical shaped wall of the fruit supporting dish 17 are maintained on the periphery of the dish and held there with the holding force exerted upon the supported fruit piece being provided by the gate element 75 pressing inwardly toward the center of the rotation of the frustoconical dish.

If now it be assumed that the dish 17 is an element which, looking at FIG. 2 for instance, has a peripheral extent of say 25 ft. (this means it is approximately 8 ft. in diameter, measured at the midpoint between the guide tracks 77), and if it be assumed that the driving motor 23 and the drive mechanism rotates the dish 17 at a rate of 40 r.p.m., the peripheral speed of each article held by the gate 25 adjacent the guide track 77 will be approximately 1,000 ft. per minute. This being the case, it can be appreciated that if the restraining force exerted by the gate 75 is suddenly removed, the article or fruit piece 11 which had 'theretofore been held by the gate, will tend to travel in precisely the same direction it had been moving at the time the force was removed, subject, of course, to the effects of gravity acting thereupon and such wind frictional losses and the like as may occur. This means that at the instant when the gate 75 is opened by some appropriately controlled mechanism, later to be described, the fruit piece, previously held in the gate, will move away from the frusto-conical dish periphery in a direction precisely tangent to the dish periphery (see FIG. 2 for instance) and the gate then will empty.

According to the invention herein to be described, and as will be later mentioned, the gate 75, after once having opened, will promptly close of itself (as later to be set forth in detail), and will assume the general position shown in FIG. 1. This fact will be true regardless of whether or not a fruit piece is present. All supported fruit pieces will be dicharged at some point during the dish rotation between the exploration point, as diagrammatically shown by FIG. 2, and the point where the cam track 69 rises (which point, it will be recalled, is still further along the arcuate path following the last discharge point).

It will be seen, if the fruit piece resting upon the outermost lifting element 59 can be lifted so that the restraining force exerted against this fruit piece by the fruit locating vane 47 is no longer effective, that particular fruit piece will move outwardly by centrifugal action from and olf the lifting element 59 and into the gate 75 to be supported by the gate and located by the guide tracks or wires 77. The precise manner in which the pieces actually move is unimportant to this consideration so long as it is understood that the particular fruit pieces actually move to the indicated position within the gate. Specifically, the actual shuffle element to achieve this result is not a part of this described invention but is exemplified in one convenient form which has been used successfully to move the fruit pieces from one circular region of the dish outwardly toward the periphery finally to locate in the gates.

With the timing of the operation of the lifting elements being such that each shufile component to move the fruit toward the gate occurs at a like point in the dish rotation, first the outermost, or that nearest the gate, is lifted as its follower 63 moves over'the portion 81 of the outer cam track 69. This, it will be observed, enables the outermost lift position to be cleared of fruit prior to the time when the lift of the next inwardly positioned lifting element occurs. Then, with the central cam track 67 having its lift position located as indicated at 83 on FIG. 3 to follow the lift position 81 in time, an effect similar to that explained with respect to the lift element 59 occurs insofar as the lifting element 57 is concerned, and, as the cam follower 63 reaches the rise point 83 on the cam track 67 with rotation of the dish, the lifting element 57 is moved upwardly until the fruit piece 11 thereby held is moved clear of the force exerted against it by the stationary fruit locating vane 45.

The fruit piece 11 having been lifted is now permitted to roll to rest upon the next outermost lifting element 59 against the force exerted on it by the locating vane 47. The lifting element 57, after returning to its lowermost position as the cam follower 63 rides beyond the downward slope of the portion 83 on the cam track, is clear of all objects so that when a similar lifting operation is effected upon the innermost lifting element 55 at a later time in the cycle, to move the thereby held fruit piece 11 upwardly so that the inward force exerted upon it by the locating vane 43 is removed, the fruit piece previously held upon the lifting element 55 then comes to rest upon the lifting element 57 and is replaced by that fruit piece 11 which is adjacent to the piece indicated by the drawing as resting upon the lifting element 55. This last named piece is then replaced by that piece which moves up the sloping wall 87 which forms the outer periphery of the flat section 15 of the frusto-conical dish 17.

The various fruit pieces 11, as they are supplied upon the flat section 15 of the frusto-conical fruit supporting dish 17 by way of the chute 13, as already noted, first come to rest at a region where the flat portion is turning very slowly so that there is a minimal relative rotary movement at the discharge point of the chute. However, the fruit pieces, when resting on the flat portion of the rotary dish 17, tend to move along a tangential path with respect to the radial distance out from the center of the dish. As this occurs, the motion, gradually, although always tangential but for very short distances, is as if the fruit pieces were traveling a more or less helical or spiral path out to the position of the sloping wall 87 so that they are ready, as soon as the fruit piece 11, carried on the most inwardly positioned lifting portion 55, is moved off to replace that fruit piece, whereby the gates are kept continually filled when the sequence of movement is maintained.

The actual coloration of the lemon in the selection operation is determined by exploration. To this end each lemon, soon after it has been loaded within the gate, is caused to be illuminated from all directions, and explored by a light scanning mechanism to determine its light refiectance at different illuminating light wavelengths. This mechanism is represented at 89 since it has, per se, been explained in copending application Serial No. 322,267, filed November 24, 1952, now US. Letters Patent No. 2,933,613, granted April 19, 1960, and the precise form of the light scanner is not the subject matter of this particular invention except that the signal output must be suitable for activating the instant apparatus. Sufiice it to say that the exploring means provides for illuminating each individual fruit piece as it passes before the reflectance responsive means with light of substantially monochromatic characteristics rapidly switched between two different regions of the visible spectrum. The light is directed to strike the individual fruit pieces from substantially every angle, that is, from the top, the bottom, the front, the rear, and each side, as well as from other angles to illuminate the surface regions between the various mentioned portions. Reflected light from the fruit is then directed to fall into light translating tubes or phototubes in which the current flow is determined by the amount of infalling light. i

The phototubes are arranged in distributed fashion and in a sufficient number that the signal output from the combined group is an integrated signal representative of the average light reflectance at the particular illuminating light wavelength over as close to the entire surface of the fruit as is possible within commercial practicability, bearing in mind that sorting accuracy is determined by the accuracy of the integrated signal values developed.

As was explained in the copending application, aboveidentified, the illumination of the object occurs at each of two different substantially monochromatic illuminating light wavelengths with extremely rapid switching between eachduring the exploration. This means that each object in the gate is subjected to illumination at each light Wavelength a substantial number of times during the very brief exploration period. In this Way it is possible to produce from the phototube output a control signal which is a true measure of the surface reflectance at each of the selected light values. Applicant has termed the signal resulting from this exploration as the IVR or a signal which may otherwise be-expressed as the Index of Variation of Reflectance.

Various connections may be utilized for connecting together the various phototubes and some of those which have proved satisfactory are disclosed in applicants copending application Serial No. 693,137, filed October 29, 1957, now US. Letters Patent No. 2,946,894, granted July 26, 1960, and entitled Light Control Signal Generator. Likewise, the rate at which the switching between the two different exploring light wavelengths occurs can be controlled in various ways. In one form this method may be by a vibrating member and in another form it may be by a rotary member. Included among the forms which have already been used is that which has been shown in applicants first herein referred to copending application Serial No. 322,267, now US. Letters Patent No. 2,933,613. Other satisfactory forms are described by applicants copending application, Serial No.

674,525, filed July 26, 1957, now US. Letters Patent ,nating Device.

The signal output derived in accordance with the teachings of the foregoing applications becomes available in the output of a scanner amplifier, conventionally represented at 91. This component receives its input signal from the light scanner and phototube combination, conventionally represented at 89, although not here shown in detail. Then, as will herein be further explained, the signal output from the scanner amplifier is effectively used in accordance with changes in the output level thereof to designate different colors of the articles in the gates and therefrom, through control circuitry, to cause the gates 75 to open at selected positions about the periphery of the frusto-conical member 17. When a gate opens the fruit piece supported between the gate member 75 and the gate tracks or wires 77, is released because the gate opening removes the holding force and permits the fruit piece to move away from the dish periphery along the tangential paths already described.

It is usually desirable to have the fruit pieces indicative of one particular color (in the described form this will be the dark green pieces) discharged at a point coinciding with that of exploration. This is possible because the response of the circuit is so rapid, as compared to the motion of the frusto-conical dish, that the electrical circuit responds in a time within which but a negligible angular rotation of the dish can occur between the point of object scansion or light exploration and the first point at which discharge can take place.

Under the circumstances, it can be assumed that the signal pulse output (which will later be further explained) of the scanner amplifier 91 is a maximum when a dark green lemon is explored. For this condition the discharge point for dark green may be represented at point 93. Similarly, point 95 may represent the discharge point for light green lemons. Points 97 and 99 may, respectively, represent the discharge points for silver and yellow. For simplifiction of operation, as well as the magnetic memory circuitry used, the point 99 for discharging yellow lemons may be considered also as that point in the operation where all gate-supported articles which have traveled between the point of scansion (also the first discharge point) 93 and point 99 will be removed so that at the loading position 101, which follows as the dish rotates, each gate will be empty and ready to receive another object.

Referring now particularly to the gate operating mechanism, as depicted in one form by FIG. 1, it can be seen that the gate itself is in the nature of a generally U-shaped wire-like element arranged to move about its pivot point 103. The wire-like element 75 may be wrapped around the pivot 103 and, for instance, welded thereto in a way to extend beyond the same, more or less as a bell crank, with the downwardly depending arms 105 joined and then carrying at their outer ends a weight 107. The outer ends of the downwardly depending arms 105 are normally caught and held by the pointed end 109 of a link 111 which is pivoted to the frame of the drum on the spindle axis 113. The link 111 is held in this position by the action of a spring 115 having one end connected to the pivoted arm and the other end connected to the dish frame.

When the signal output from the scanner amplifier 91 becomes effective through actuation or energization of a thyratron type gaseous discharge tube, later to be described herein in connection with the showing of FIG. 5 in particular, a current is caused to flow through the winding of the electromagnet 119 which is supported from a support bracket 121, extending outwardly from the frame of the frusto-conical dish. The resultant electromagnetic force exerted on the magnet armature 123 draws this armature inwardly of the magnet 119 and thereby, due to the connection of this magnet armature at its outer end 125 to the link 111, releases the hooked end 109 from the weighted end of the downwardly depending arm 105. Since the weight of any fruit piece 11 within the gate 75 is greater than that of the weight 107, the complete gate, acting as a bell crank, with release from the hooked end, tends to rotate about the gate pivot axis 103 to an extent such that the fruit piece 11 is no longer held between the gate arms 75 and the guide tracks or wires 77 but is free to escape, as it were, and to follow a tangential path from the periphery of the frusto-conical dish, with the point of tangency being at that point on the dish periphery where gate opening occurs.

The gate 75, under such conditions (due to the weight of the fruit piece 11 being greater than that of the weight 107) can rotate in a direction so as to move away from the edge of the dish, and, looking at FIG. 1 and at gate 75 in which the fruit piece 11 is shown, this will be in a clockwise direction about the pivot point 103 as its axis until the downwardly depending arm 105 contacts the stop 127. By this time, the magnetizing force, due to current flow through the electromagnet 119, has been interrupted, as will later be explained, and the electromagnetic force to draw the magnet armature 123 within the electromagnet 119 is removed. Since the fruit piece at this instant has been discharged from its position between the gate 75 and the gate tracks or wires 77, the weight 107 tends to fly outwardly and rotate the gate 75 and the downwardly depending arm 105 about its axis 103 in a counter-clockwise direction (opposite that of its previous movement).

This again closes the gate to the indicated position of FIG. 1 and since with the magnetizing force on the electromagnet removed the spring 115 is effective to turn the link 1111 about its spindle axis 113 in a counter-clockwise direction. The outer hooked end 109 then again catches the outer end of the downwardly depending arm 105 and, since the weight 107 is effective at a point below the 1 1 center of rotation about axis 103, the gate is held closed until the next succeeding pull becomes effective on the electromagnet 119. If no fruit piece 11 is in the gate at such time the gate will remain in the indicated position, but, if the gate is full, then the action above described again takes place.

It has heretofore been suggested herein that the signals developed in the scanner amplifier 91, as a result of the exploration may be assumed to have different amplitudes depending upon the color of the fruit instantaneously explored. Illustratively, the signal amplitude is exemplified, for instance, by the several wave forms shown adjacent to the conductor 129 leading outwardly from the scanner amplifier 91. Of these several wave forms the conventionally shown signal marked a'g may be considered as that representative of the reflectance from a dark green lemon. Similarly, the signal represented as lg may be considered as the signal representative of reflectance from a light green lemon. Lastly, the signal shown and designated by the letter s may be considered as that signal which is developed from exploring a socalled silver lemon. Considered from this viewpoint, the developed signals are passed along the conductor 129 to be concurrently supplied to the several tubes 131, 132, and 133. The tubes (as will later be explained) are all normally biased beyond their cut-01f state, so that the applied input signals serve as control signals to determine the output signals available from the tubes when the applied bias is overcome. Tubes 131, 132, and 133 are all preferably gaseous discharge tubes of the so-called thyratron type. The input signals are applied on the input grid or control 134, 135, and 136, respectively, by way of suitable coupling condensers 143, 144, and 145, respectively. Each of the tubes 131, 132, and 133 has its cathode 147, 148 or 149 connected to ground 150 in the manner indicated.

The tubes are all biased by a similar combination of a grid resistor 151, 152, and 153 to which biasing voltage is applied from bias sources 154, 155, and 156, respectively. Each of the bias sources has its negative terminal connected toward the tube grid or control electrode therewith associated, with the positive terminal of the bias source connected to the tube cathode and to the ground 150, as indicated.

The magnitude of the bias applied to each of the tubes 131, 132, and 133 is different. Assuming that the tube 132 is to become energized to draw current when the signal value indicative of a lemon of dark green color is developed due to the explored lemon, it will be appreciated that the signal strength must exceed the bias level shown on the curves adjacent to the conductor 129 by the bias value b if that level is applied in the tube. Likewise, if it be assumed that the tube 133 is to respond (the exclusion of tube 132) to a signal pulse indicative of a light green lemon, such as the pulse lg, it can be appreciated that the bias value applied to the grid 136 from the source 156 acting through the resistor 153 may be a value indicated by the bias level 11 on the curve. Lastly, with the assumed signal level produced by exploration of a silver lemon being much less than that produced by either the dark green or the light green lemon, the bias level which would be required to be etfective on the grid 134 from the source 154 acting through the resistor 151, may be assumed at a level 12 For each of these conditions it will be appreciated that, if a signal is present which has an amplitude level corresponding to that for'dark green and represented by the pulse dg, each of the tubes 131, 132, and 133 will pass current because the input signal is of higher amplitude than that bias applied to any of the tubes. This signal level, as will later be seen, is of an amplitude which is effective to open the gate in which a dark green lemon is positioned. The arrangement is such that the actuation of the gate operating solenoid for discharging the dark green lemon occurs at the position 93. 1f the signal Cit available on the conductor 129 due to exploring the: gate.- held lemon is only of an amplitude corresponding to that shown by the pulse lg, indicative of that representing a light green lemon, or an amplitude level shown as s, indicative of the silver lemon, it will be seen that this signal is not of sutficient strength to overcome the bias applied to the input electrode or grid of the tube 132, although the two signals will have been of sufiicient amplitude to produce a current flow through each of the tubes 133 and 131, or only the tube 131, respectively, as the case may be. It also can be stated that for the lower level signal amplitudes (as will later be more fully expressed), and illustratively, the level s, solenoid operation at point 97 can occur only when magnets 183 and 184 are of opposite polarity.

Consequently, by signal level discrimination the pulse indicative of a light green lemon is not sutficient to cause a response of that portion of the circuit which is used for a dark green indication, despite the fact that the light green signal lg will cause a response in the circuitry, segregated to light green and silver lemons. From the standpoint of forming a signal controlled operation from the scansion of a silver lemon it will be seen that the signal s is of lesser amplitude than that bias level 11 and b which has been applied to the tubes 132 and 133. Therefore, for a signal indicative of a silver lemon only the tube 131 will draw a current, this despite the fact that all of the tubes have their inputs in parallel.

Each of the tubes 131, 132, and 133 receives operating anode voltage from source 161 which is supplied upon the tube anode 157 for the tube 131; upon anode 158 for the tube 132; and upon anode 159 for the tube 133. The source 161 has one terminal grounded at and its other terminal supplies the output voltage through the conductor 163 and the windings 165, 166, and 167 and the conductors 169, 170, and 171, respectively, to

the plates or anodes of the tubes 131, 132, and 133. The

source 161 is preferably an AC. source, capable of producing a voltage wave within an amplitude range sufficiently positive to sustain current flow in the tubes during at least a portion of the positive excursion with the operating cycle repeating during each 4 of a second for the illustrated embodiment of sorting forty lemons per second. Such being the case, it will be appreciated that each of the pulses dg, lg, and s should be a maximum value during the early part of the positive half cycle of generator 161 and that this generator should be synchronized with the rate of lemon exploration. For this condition during each pulse one or more of the tubes 131, 132, and 133 will draw plate current (depending upon the input signal and the tube bias). The current fiow through the tubes will then be cut oil or arrested during the negative half cycle of the activating voltage due to the fact that the plate or anode potential of the tube will have been carried negative with respect to the tube cathode. Each of the windings 165, 166, and 167 is drapped about an iron core 173, 174, or so that current flowing through one or more of the windings 165, 166, and 167 will polarize the core so as to make its end nearest to the sorting drum 181 (herein called the inner end), such as the ends 177, 178, or 179, of one polarity or the other. For purposes of illustration let it be assumed that the polarity will be made north at the inner end of each core.

As can be seen, particularly by the showing of FIG. 5, the cores 173, 174, and 175 are positioned in the soft iron support bracket 176, which, as will later be described, forms a part of the magnetic circuit which includes the drum 181. The support spindle or axis 19 carries, in addition to the frusto-conical fruit supporting .dish 17, also the drum 181 which is secured for rotation at the same rate as the frusto-conical dish 17. The drum 181 is of soft iron and has extending outwardly therefrom a plurality of hardened steel magnets 183, 184, and 185 which are arranged one above the other so that, as the drum 181 rotates, these magnets are caused to pass 13 adjacent to the inner ends 177, 178, and 179 of the cores 173, 174, and 175. The number of sets of the hardened steel magnets 183, 184, and 185 corresponds to the number of gates 75 positioned about the periphery of the frusto-conical dish.

Of this group of hardened steel magnetic pole pieces, as can be appreciated by noting showing of FIGS. and 7 in particular, only the magnet 184 is provided with a winding wrapped thereabout. This winding is shown at 187 and is connected at one end through conductor 188 to a biasing source 189 which has its positive terminal connected to the steel drum 181. The drum 181 is electrically grounded to the point 150 by any appropriate type of ground connection, herein conventionally represented at 191. The inner end of the winding 187 connects by way of a conductor 193 to the grid or control electrode 195 of the thyratron-type gas discharge tube 117, which has its cathode element 199 grounded. The tube anode or plate 201 is supplied with operating voltage from an alternating current source conveniently represented at 203, grounded on one side and supplying the tube anode or plate 201 by way of the conductor 205 through the winding 119 of the indicated electromagnet 'which is used to control the opening and closing of the gate 75. The source 203 is of like frequency to source 161 and in phase therewith.

It will, of course, be appreciated that there is included in the device a number of thyratron-type tubes 117, windings 187, and the associated components, as Well as gate control magnets 119, which correspond to the number of separate gates 75 arranged about the periphery of the frusto-conical dish 17. The circuit diagram shows but a single thyratron tube 117 for this purpose but it will be appreciated that the exemplification of the FIG. 1 discloses a plurality of thyratron tubes 117 on the upper surface of the drum 181. With the arrangement as indicated and the gate operating magnets 119 being carried upon a support either connected to or associated with the frusto-conical dish, the connections between each thyratron tube 117 and its associated gate control magnet 119 may be arranged in any desired fashion. For convenience of illustration this has not been shown, although it should be clear that the wiring connection can proceed through or about the shaft 19 and thence outwardly to the several gate control magnets 119.

The operation of the gate control magnets accordingly is established at the time the hardened steel magnet 184, with its winding 187, one being provided for each individual thyratron tube 117 and thus one for each gate, comes within the region whereat a current pulse is induced through the winding 187 due to the core 174 acting directly, or to effect produced by cores 175 or 173 on magnets 185 or 183 becoming effective through the magnetic shunts 209 or 215 (later to be further explained) on magnet 184, or to the wipe magnets 217 acting on all magnets 183, 184, and 185, thereby to control the thyratron tube 117 and its associated controlled gate.

In this form of operation the generator, conventionally shown at 203, may be of any desired type but, for purposes of ready appreciation of one form of device, it may be carried directly upon the drum 181 (see FIG. 1) and arranged to move with the drum. By means of a pinion gear 207 which meshes with a ring gear 208 it is feasible to drive the generator through suitable gearing output at the desired speed so that an AC. output will be arrived at merely through rotation of the drum, although various other forms of control may be utilized. The generator 161 may be similarly controlled and synchronized with the generator 203.

The operation of the fruit discharge gate control will be more fully appreciated by making particular reference for a moment to the showing of FIG. 6 which sets forth in expanded, broken-away, developmental form the periphery of the drum 181 from which the hardened steel magnets 183, 184 and 185 extend (preferably in colum- 14 nar arrangement) in uniformly spaced positions corresponding in number to the number of fruit discharge gates about the periphery of the frusto-conical dish 17. It should be remarked that in the viewing of the expanded portion of the drum 181, as shown by FIG. 6, the left and right hand edges must be assumed to meet to form the circular drum periphery.

Considering now the showing of FIGS. 2 and 4, the wipe and yellow lemon discharge position, marked 99, represents that at which all gates 75 have been opened once in passing (looking at each of FIGS. 2 and 4 for instance) in a counter-clockwise direction (as suggested by the arrows) between the position marked load and the point 99. Such drum movement carries the drum base (and, of course, the gates) past the exploring point 93 and the sequence points whereat dark green, light green and silver lemons, respectively, are to be discharged.

At the final discharge point 99 each of the hardened steel magnets 183, 184 and 185 comes beneath one of the strong permanent magnets 217, each of which, for the example here given, is a very strong magnet capable of inducing a north pole at the outer end of each of the magnets 183, 184, and 185. This being the case, it will be appreciated that with the Winding 187 about the magnet 184 a pulse of current will flow through this magnet winding simultaneous with the change in the magnetic state of the magnet 184. Current flow in winding 187 controls the potential upon the grid or control electrode of the gas discharge or thyratron tube 117 relative to the tube cathode. The circuit completed for this purpose is from the battery or source 189 (having its positive terminal connected to the drum), the conductor 188, the winding 187, the conductor 193, the grid or control electrode 195 of the tube 117, the cathode 199 of the tube and the steel drum 181, back to the source or the battery 189 serving to bias the tube 117 to the desired threshold potential. 7

It will thus be seen that the strong permanent magnets 217 control the polarity at the outer ends of each of the magnets 183, 184 and 185 and, in doing so, cause (through winding 187 of magnet 184) a change in the potential on the control electrode of the thyratron tube 117.

The thyratron tube 117 has its plate or anode 201 connected through the source 203 to ground 150 by way of the conductor 205 connected through the winding of the electro magnet 119, which controls the operation of the gate 75. Consequently, for at least a part (determined by the bias level set) of a positive half cycle of the generator or AC. source 203 current can flow through the tube 117 to actuate the magnet 119 if during such period the control electrode 195 is carried to a potential to overcome the tube bias due to a current pulse being induced in the winding 187. This being done, the hooked end 109 of the link 111 is released from the downwardly depending arm 105. If at this instant a fruit piece 11 is within the gate 75, the gate can open because the weight of the fruit piece will permit the gate arm to rotate clockwise about pivot point 103 against the force exerted by weight 107. If the gate 75 is unloaded, the weight 107 on the arm 105, although the arm has been released, is sufiicient to hold the gate 75 closed because the weight tends to rotate the gate arms about pivot point 103 in a counter-clockwise direction.

With this explanation it will be appreciated that at the position 99 all gates 75 must be emptied of fruit by opening (in the event they had not previously opened) before the frusto-conical drum turns further in a counter-clockwise direction, following the manner in which the invention has been illustrated, so the re-loading of the gates in the fashion herein explained can occur in the region between the position 99 and the exploration point indicated at 93. The point 99 represents the final discharge of all fruit and the last position of gate opening in the event any gate had not previously been opened during each turn of the drum.

It has already been explained that exploration of the fruit pieces held within the gate 75 produces various signal amplitudes, such as dg, lg, and s, indicative of fruit of the colors dark green, light green, and silver.

For all fruit pieces except those which are discharged at the position 99, it was also explained in what has gone before that, depending upon the amplitude of the produced voltage pulse constituting an output from the scanner amplifier 91, one or more of the thyratron tubes 131, 132, and 133 pass current at the instant the pulse is developed. Since the output circuit of each thyratron tube 131, 132, or 133 is through one of the windings 165, 166, and 167 and the source or generator 161 to ground 150, with each of the cathodes of the tubes also grounded, it is evident that at least one of the windings 165, 166 or 167 will pass current at such times.

Considering now the gate discharge position immediately prior to the final discharge gate position 99, it will be borne in mind that this is represented by the position 97 whereat silver lemons are assumed to be discharged (since lemons of the color light green and dark green have previously been assumed to have been removed from gates 75 about the periphery of the frustoconical drum 17), This condition is produced by virtue of the fact that a signal of the amplitude s is sufficient to overcome the bias b,, applied by the source 154 to the thyratron tube 131, and thereby permit current flow through the thyratron tube 131 for at least a part of the positive half cycle of the source 161. Current flowing through the tube 131 when produced by the out put conductor 129 had acted to produce a north pole at the end 177 of the core 173 which faces the drum 181. A north pole at end 177 will induce a south pole at the outer end of the magnet 183. With this polarity induced and retained, as soon as the drum 181 rotates to a position where the magnet 183 comes beneath the magnetic shunt 215 the silver lemon will be discharged. This occurs at a position corresponding to that used to discharge silver lemons. Since, relatively speaking this operation will be similar to that which occurs when a light green lemon is discharged at point 95 (except for the light green condition in the permanent magnets 184 and 185 come beneath the magnetic shunt 269) the operation will be described further relative to the discharge of light green lemons.

At the moment either magnets 183 and 184 (for silver lemons) simultaneously come beneath the magnetic shunt 215 or the magnets 184 and 185 simultaneously come beneath shunt 209 a similar condition is brought about. At each state (if the outer end of magnets 183 or 185 is carried to a south polarity for the example given) a current pulse is induced through the winding 187 about the hardened steel permanent magnet 184 to cause a change in potential on the grid or control electrode 195 of the tube 117 in the direction to cause current flow through the tube 117 and thus through the magnet 119 to open the gate 75 as the gate passes position 97. If the gate is loaded with a lemon, the gate opens in the fashion already explained. If the lemon has previously been discharged from the gate because the lemon was either of a light green or dark green hue (as will be explained), the gate remains closed and the frusto-conical dish 17 passes beyond the point 99.

So considered, at this time reference may be made to the discharge station which is immediately ahead of the point 97, that station being one represented at 95, whereat light green lemons can be discharged. If a light green lemon is to be discharged, it will be recalled that the output pulse from the scanner amplifier 91 is of an amplitude represented at lg. Bias on the tube 133 is applied to a level 11 Therefore, only at times when a voltage pulse of at least the amplitude lg is applied to the tube grid or control electrode 136 will it be possible for the tube 133 to pass current even for a portion of the positive half cycle of the source 161. It, of course, will be apparent that the operating condition where the tube 133 can pass current due to the level of the input pulse is one where the tube 131 can also simultaneously pass current, but since tube 133 controls the discharge position ahead of that controlled by the tube 131, the fact that the latter tube also passes current is of no significance as far as fruit discharge is concerned because the tube 133 must operate to open the fruit discharge gate at assumed point 95.

Now, to consider the precise discharge action at either of points or 97 first, suppose the gate 75 contains a light green lemon. Prior to the introduction of this lemon to the gate, the wipe magnet 217 has magnetized the magnets 184 and 185 to saturation producing a north pole on the outer end of each and a south pole on the inner end. Some of this magnetization is still retained at the time the drum has turned to position 95 by virtue of the properties of the hardened steel used in the construction of magnets 184 and 185.

When the lemon reached the scanning point 93, the signal designated lg was produced by the scanner amplifier 91. This signal initiates current flow in the thyratron 133 since the source 161 is so phased as to produce a positive voltage at this instant. (The current produced simultaneously in thyratron 131 is ignored for the moment since it is not germane to the present consideration.) This current, flowing in the Winding 167, magnetizes the soft iron core producing a north .pole on the end thereof designated 179. Flux flows in the magnetic path comprising the soft iron core 175, the air gap between the core 175 and the hardened steel magnet 185, the magnet 185, a portion of the soft iron drum 181, the air gap between the drum and the soft iron bracket 176, and thence through the bracket 176 to the core 175. The windings and current are so proportioned that this flux is great enough to saturate the hardened steel magnet 185. This reverses the magnetization of magnet 135, producing a south pole at its outer end and a north pole at its inner end.

Thus, as the drum 181 carries the magnets 184 and 185 toward the magnetic shunt 209, the magnets 184 and 185 are magnetized to the same strength but in opposite polarity. As the magnets approach the magnetic shunt 209, flux flows in the path including the magnet 184, the air gap between magnet 184 and magnetic shunt 209, the magnetic shunt 209, the air gap between shunt 209 and magnet 185, magnet 185 and the soft iron drum 181 in which magnetomotive forces associated with the magnets 184 and 185 are series aiding. This flux increases rapidly as the magnets approach juxtaposition with the shunt, inducing thereby a voltage in the winding 187. As the magnets 184 and 185 recede from the shunt, this flux decreases rapidly producing a voltage of opposite polarity in the winding 187. The voltage produced in winding 187 can have either a wave form which rises from a zero value to a maximum crest and then goes through the remaining 270 of one cycle passing through the zero again when the shunt and magnet are in juxtaposition and then goes through the negative half cycle or the form may be one which first goes through the negative half cycle and then after going back through a zero value rises to the positive crest and then to zero. The direction depends upon the polarities of the magnets and the direction of the winding 187. In either case, the negative pulse is not elTective in initiating current flow in any .thyratron 117 and can be ignored. The positive pulse causes release of the lemon through control of the position along the designated flux path, and only a small change in the fiux through the coil 187 would have occurred as the magnets passed the shunt.

It is furthermore clear, but not important, that a dark green lemon will cause reversal of the polarity of both magnets 1.84 and 185. Thus, only an incidental signal is produced by the magnetic shunt 209, and the solenoid 119 will not be energized at position 95.

The action of the shunt 215 in releasing a silver lemon is, of course, analagous to the release of a light green lemon by the magnetic shunt 209.

Reviewingbriefly, tube 133 in passing current causes a north pole to be produced at the end 179 of the soft iron core 175, which end is nearest to the magnet 185 extending outwardly from the periphery of the-drum 181. With this condition obtained, the outer end of the hardened steel permanent magnet 185 is then caused by magnetic induction to assume a south polarity coincidentally with fruit exploration by the scanner amplifier. Then, as the drum 181 continues to rotate (counter-clockwise, looking at FIG. 4) each of thehardened steel permanent magnets 184 and 185 simultaneously comes beneath the magnetic shunt 209 which shunt is positioned adjacent to the drum 181 at the discharge position for light green lemons so that arrival of the magnets 18 1, and 185 beneath itv can control the discharge of only the light green lemons at the point 95. The condition hereina'oove explained then results in a current pulse in the winding 187 which, as before noted, provides a grid control potential change on grid 195 of the tube 117 so that current can flow in this tube for at least a portion of one positive half cycle of the generator 203 but is-cut off as the generator goes through the negative half cycle. The flow of current in tube 117 causes the gate 75 to open at position 95 to discharge any lemons held in the gate 75. It no lemon is held in the gate (indicating that the lemon has been discharged as a dark green lemon at the position of scanning 93 reached before turning to position 95) it will be appreciated that the magnet 119 is not again energized as it reaches position 95, as already explained, since the gate had previously been opened and gate operation would only occur when magnets 184 and 185 are, of different polarity.

This having been explained, it is apparent that the only remaining position on the frusto-conical dish where lemon discharge can occur, is that position which coincides with the point of exploration, namely point 93. At this point, discharge must be indicative of lemons which are of dark green color. The dark green lemons produce as an output pulse from the scanner amplifier 91 a voltage pulse represented by the amplitude of the wave form dg. The bias voltage applied to the tube 132 by source 155 is set at a level b Consequently, since a voltage pulse of the amplitude dg" is of greater amplitude than the bias applied to any of the tubes 131, 132, and 133 it can cause current flow through all of tubes 131, 132, and 133. Since the drum 181 is assumed to be rotating, the hardened steel permanent magnet 184 passes beneath the end 178 of the core 174, which is caused to assume a north polarity by current flow through the tube 132, coincidentally with the time output current from tube 132 flows in the winding 166 so that a current pulse is at once also induced in the winding 187 to produce (or initiate) current flow in tube 117 thereby to operate the electro magnet 119 in the fashion already explained.

At the first or exploring position 93 at which dark green lemons are discharged each gate 75 about the periphery of the frusto-conical dish 17 is filled with a lemon. magnet 119 to release the hooked end 109 of the link 111 permits the weight of the fruit 11 within the gate to cause the gate 75 to open. If this accurs, discharge of the dark green lemon at once takes place. If the gate 75 is not released at position 93 (due to it holding a lemon of some color other than dark green) the operation previously described will occur.

Consequently, at this position operation of the As a corollary to What has been described above it may be pointed out that as the drum 181 and the frustoconical disk 17 rotate (counter-clockwise as depicted) fruit is loaded into the gates 75 following its passage past an assumed final discharge point. This occurs prior to time the particular gate reaches the exploration point 93 and the dark green discharge position. From what has been stated it can be appreciated that if the explored fruit is of an assumed dark green color discharge will immediately occur because the scanner amplifier 91 produces an output pulse of a level sufficient to overcome the bias upon the tube 132 to cause current to flow in the tube during at least a part of the positive half cycle of the source 161. When this occurs, the core 174 is magnetized so that the core end 173 instantly adjacent to the outer end of the hardened steel permanent magnet 134 passing therebeneath induces current pulse inthe winding 187 and a consequent operation of the tube 117 during at least a part of the positive half cycle of the source 203. Where the sources 161 and 203 are operating in phase and in synchronism current flow through the tube 117 and the electro magnet 118 will cause discharge of the dark green lemon coincidentally with its scanning.

If the scanning operation at point 93 produced a signal of a level indicative only of light green, such as the pulse lg (see FIG. 5), the induced polarity change at the end of the core which was instantly adjacent to the hardened steel permanent magnet 185, while effective to change the polarity of the outer end of the magnet 185, cannot produce a current pulse in the winding 187 until the hardened steel magnet, and with it the drum, have rotated through an angle corresponding to the spacing between point 93 and point whereat the light green lemon is discharegd. Then, as above explained, passage of the hardened steel magnets 184- and 185 simultaneously beneath the magnetic shunt 299 will produce a pulse in the winding 187 to establish a controlled operation of the electro magnet 119 to discharge a light green lemon at point 95 as above explained.

Next, if the output from the scanner is of a level only equal to that shown by the pulse s on FIG. 5 it, while the current flow through the tube 131 would be suflicient to establish a change in the polarity in the outer end of the permanent magnet 183 at the instant when the end 177 of the core 173 was instantly adjacent to the magnet 183 (and this would coincide with the time at which the cores 174 and 175 were adjacent to the magnets 184 and 185, associated with the gate in which the exploration instantaneously occurred) could not discharge the fruit in the fashion above explained until the permanent magnets 183 and 184 rotated a further angular distance in a mum ter-clockwise direction to bring them concurrently beneath the magnetic shunt 215. When this condition occurred the silver lemon would be discharged in the fashion already explained.

Lastly, since a lemon of a color yellow (which would: be the remaining classification of the complete roup) would not produce a signal output from the scanner amplifier 91 sufficient to produce a signal pulse of even as low as amplitude as the pulse s, none of the tubes 131, 132,

or 133 could conduct due to a voltage pulse on line 129.

Therefore, no discharge of fruit could occur at any of the points 93, 95 or 97 unless lemons of dark green, light green, or silver color hadbeen held in the gate. It is to take care of conditions where lemons of yellow color (or even culls) are present that the permanent magnets 217 are located at the wipe and yellow discharge positions 99 to accomplish two purposes of which the first is to discharge any fl'lllt remaining within the gates, and the second is to bring back to a proper polarity each of the magnets 183, 184 and 185 which amounts more or less to a recycling of the operation at each turn.

FIG. 7 illustrates in purely conventional manner one form of support for the magnetic shunt 209. The support is in the form of a nonmagneitc bracket member 211 ate-sa a to which the soft iron member or magnetic shunt 269 is secured. The nonmagnetic bracket 211 is then secured in any desired fashion to the frame 213. The length of the magnetic shunt 209 is that which is required to span the vertical separation between magnets 185 and 1%.

The second magnetic shunt 215 spans the vertical height on the drum 181 between the magnets 183 and 184, but, as already suggested, this magnetic shunt is located at the region where the so-called silver lemon would be discharged (see region 97 on each of FIGS. 2 and 4).

From what has been said, it will be appreciated that that memory is built into the unit in such a way that if the exploration of the lemons to measure their light reflectance is such that the signal indicative of the reflectance (the index of variation of reflectance) is a pulse of minimal amplitude, such as pulse s in FIG. 5, the gate 75 cannot open until the drum has turned to the position 97. If, however, the signal pulse (such as the pulse lg) is indicative of a light green lemon, the gate will open first at the position 95, whereas for the dark green lemon the gate will open, as first explained, at the position 93, corresponding substantially to that point at which exploration takes place.

Consider now a condition where the lemon within the gate is a lemon which is both ripe and mature and, therefore, one which is of the yellow classification, the scanner 89 will not produce any pulse output signal on the conductor 129 which even reaches the bias value bs. Therefore, with a yellow lemon within the gate, no control of the gate opening can occur by virtue of any current fiowing through any of the windings 165, 166, or 167 to polarize any of the magnets 183, 184, and 185. Therefore, to discharge lemons from the gates subsequent to the frusto-conical drum passing the discharge position 97 for a silver lemon, the control is achieved by virtue of a very strong permanent magnet, designated at 217 on FIG. 6. This magnet is arranged adjacent to the drum at the discharge position 99 and is strong enough both to polarize each of the magnets and simultaneously to induce a powerful current through the winding 187 completely independent of any conditions which have occurred at any of the prior stations 93, 95, and 97. Consequently, as the frustro-conical drum rotates, the permanent magnet 217 at position 97 causes each gate operating magnet 119 to be momentarily energized as the drum turns to bring the individual gate to the discharge point. Any gate-supported objects not previously discharged are thus released at point 99 so that, with the gates then abruptly closing, in the fashion already explained, reloading can occur at the point 101 as the drum completes the revolution and commences its next rotation, during which the explained events are repeated. Further gate openings will then occur when the next gate-supported lemon is explored for light reflectance.

From the foregoing it will be apparent that the invention may assume various forms and that the operation is so constituted that the lemons will be explored in sequence, later to be discharged one at a time, during each rotation of the frusto-conical drum.

Having now described the invention, what is claimed is:

1. In sorting apparatus, a rotary article support, a plurality of article holding gates distributed about the periphery of the support, means to introduce articles upon the support for filling the gates from an internal point, and means to open the gate members outwardly subsequent to filling one by one at selected peripheral points to release each article along a path substantially tangentially of the rotary article support.

2. In sorting apparatus, a rotary dish-shaped article support, a plurality of sequentially arranged article holding gates arranged about the periphery of the support, means to introduce articles upon the support to fill the gates one by one from a region located internally of the support, and means to open the gate members outwardly subsequent to filling one by one at selected positions during support rotation to release each article along a path substantially tangentially of the rotary article support.

3. In sorting apparatus, a rotary article support, a plurality of article holding gates distributed about the periphery of the support, means to introduce articles upon the support for progressively filling the gates from an internal point, and means to open each gate once during each rotation of the support to release the supported article from the support periphery along a path substantially tangentially of the support, and means to control the position at which each gate opening occurs.

4. In sorting apparatus, a rotary article support, a plurality of article holding gates distributed about the periphery of the support to exert a radially inward force, means to introduce articles upon the support for filling the gates from an internal point, and magnetically controlled means to open the gate members subsequent to filling one by one at selected peripheral points to permit tangential discharge of a held-article with support rotat1on.

5. In sorting apparatus, a frusto-conical article support dish, means to rotate the dish, a plurality of normally closed article holding gates uniformly distributed about and secured to the dish periphery, means to supply articles to the rotating support dish within the dished-out portion thereof in a region where its rotational speed is low relative to its peripheral speed, means to transfer articles from the supply position one by one along the conical dish-wall to sequentially fill the gates from a point internally of the dish periphery with the filling occurring at one selected position during dish rotation, means to explore the articles subsequent to their filling the gates at a region adjacent to one gate position thereby to determine the characteristics of the sequence of held articles, and means to release the gates individually during dish rotation at selected positions between exploration and reloading to segregate the explored articles into like classifications.

6. In sorting apparatus, a generally frusto-conical dishshaped article support, means to rotate the support about its axis with the dish-shaped support in an up-turned position so that its larger diameter is at its top position, a plurality of sequentially arranged normally closed article holding gates forming substantially a continuation of the conical Wall and providing the periphery of the dishshaped support, means to introduce articles within the dish-shaped support during its rotation at a region internally of the support where the diameter is substantially minimal, means to move the introduced articles progressively outwardly along the conical wall of the support to fill the gates one by one from within the support during support rotation, means to release the gate members from the normally closed position one by one at selected positions during support rotation, and means responsive to a color measurement of the gate-held articles to control the position of the gate opening in accordance with the characteristics of the articles instantaneously held.

7. In sorting apparatus, a generally frusto-conical dishshaped article support, means to rotate the support about its axis with the dish-shaped support in an up-turned position so that its larger diameter is at its top position, a plurality of sequentially arranged substantially uniformly spaced outwardly opening article holding gates forming the periphery of the dish-shaped support, means normally holding the gates, closed, means to introduce articles within the support during its rotation at a region internally of the support where the diameter is substantially minimal, means to move the articles also during rotation progressively outwardly along the conical wall of the support to fill the gates one by one from within the rotating support at one loading position, means to explore the articles following loading within the gates during the support rotation, means controlled by the exploring 21 means to release and open the gate members one by one at selected positions during support rotation.

8. Sorting apparatus comprising a rotating frusto-conical dish, means to supply and transfer articles for sorting at an input region located generally centrally of the concavity of the dish, a pluralityof normally closed gate-type article supports spaced uniformly in sequence about and secured to the periphery of the dish and adapted to receive the articles one at a time from the dish, means adjacent to the dish periphery for exploring the articles in sequence subsequent to their being loaded in the gates thereby to determine the characteristics of each article held, means for normally holding each of the gates in closed position in a range of peripheral travel of the dish between the point of article receipt and a final discharge point, the said exploring point being located between the said loading and final discharge points, and means for controlling the gate operation to change each gate to an open position at a discharge position between the peripheral exploring point and the final discharge point under the control of the exploring means and in accordance with the article characteristics thereby to discharge the articles individually along one of a plurality of separate tangential paths each originating at a point of opening position.

9. Sorting apparatus comprising an up-turned rotating article-support dish, means to rotate the dish, means to supply articles for sorting at an input region located within and generally centrally of the dish, a plurality of gate-type article supports spaced uniformly about and secured to the periphery of the dish, means to permit the articles supplied to the dish to move with dish rotation so that one at a time articles are transferred from the dish to the gate-type article support at one position of the dish due to the exerted centrifugal force, means adjacent to the dish periphery for exploring the articles in sequence during dish rotation thereby to determine the characteristics of each article held, means for normally holding each of the gates in closed position in a range of travel of the dish periphery between the point of article receipt and a selectable final discharge point, the said exploring point being located adjacent to the dish periphery and to the gate-loading point, and means for controlling the gate operation under control of the article exploration means to open each gate to an article-discharge position between the exploring point and a selectable final discharge point in accordance with the article characteristics thereby to discharge the articles individually along one of a plurality of separate selectable tangential paths each originating on the dish periphery.

10. The apparatus claimed in claim 9 wherein electromagnetic means control the gate opening.

11. Sorting apparatus comprising an up-turned rotating dish, means to supply articles to be sorted at an input region located generally centrally of and within the dish, a plurality of gate-type article supports uniformly spaced in sequence about and connected to the periphery of the dish, means operating with dish rotation to transfer the articles one at a time from the central area of the dish to the gates at one rotational position of the dish, means adjacent to the dish periphery for exploring the articles in sequence subsequent to their transfer to the gates thereby sequentially to determine the characteristics of each article held and to produce from each article a signal indicative thereof, means for normally holding each of the gates in closed position in a peripheral travel range of the dish between article receipt and a final discharge point, the said exploring point being located substantially adjacent to each of the dish periphery and the point where article loading of the gates occurs, means to release each gate type article support, and means controlled by the produced signal energy for initiating a gate-opening operation at an article discharge position between the exploring point and the final discharge point, the exploring means and produced signal energy indicative of the article char- 22 acteristics thereby establishing a discharge of each article along one of a plurality of separate selectable tangential paths each originating on the periphery of the dish.

12. Article sorting apparatus comprising an upturned rotatable dish member, means to rotate the dish, means to supply articles for sorting at an internal input region located generally centrally of the dish, a plurality of gatetype article supports secured to and spaced in sequence about the dish periphery, means for moving the articles into the gate-type article supports one at a time with dish rotation and with the aid of centrifugal force due to such rotation and at one angular position in the rotational movement the articles move from the central to the peripheral region of the dish, means for opening and closing each gate once during each complete rotation of the dish with each gate being empty and closed at the article loading position, an article exploring means adjacent to the dish periphery for determining in sequence the characteristics of each gate-held articles and developing for each explored article a signal pulse indicative thereof, the said exploring point being located adjacent to the loading point and to the dish periphery beyond the loading point, and memory means responsive to the produced signal pulse developed for each explored article for selectively opening each gate under the control of the said signal pulses developed by the exploring means to open the gates selectively to discharge the gate-held articles selectively along one of a plurality of separate selectable tangential paths each originating at the dish periphery, each path being in accordance with the article characteristics so that the discharge point for all like characteristics articles is uniform.

13. Article sorting apparatus comprising an upturned frusto-conical rotatable dish member, means to rotate the dish about the cone axis, means to supply articles to be sorted at an input region located generally centrally of and internally of the frusto-conical dish, a plurality of gate-type article supports spaced in sequence from the upturned dish walls and attached about the dish periphery, means for removing the supplied articles one at a time into the article supports at one angular position of the dish so that the articles, with dish rotation, move progressively outwardly from the central-to the peripheral region of the dish with the aid of centrifugal force provided by dish rotation, and article exploring means adjacent to the dish periphery for individually exploring the sequence of articles promptly following the positioning of each within the gate-type article support to develope a sequence of control signal pulses, the individual pulses being characteristic of each instantaneously gate-held article, means for normally holding each of the gate-type article supports in closed position in a range of travel of the dish periphery during its rotation between the point of article receipt and a selectable final discharge point, means at the final discharge point for opening each thenload gate-type article support to discharge the held article and to permit the gate-type article support to close so that an empty gate-type article support can subsequently receive an article at the loading position, a plurality of normally inoperative means located between the exploring point and the final discharge point to control, upon energization, gate-type article support opening prior to the rotating dish reaching the final discharge point, and memory means associated with the gate-type article support and responsive to the developed original pulses for,

selectively opening the gatetype article support under the control of the signal pulses developed by exploring means to'open the gate-type article support to discharge the articles selectively along separate tangential paths each originating at the dish periphery under control of the signals and in accordance with the article characteristics.

14. Sorting apparatus comprising a rotatable article holder, means to rotate the holder at a substantially constant rate, means to feed articles to the holder at a centrally located receiving area where the holder has low velocity relative to its peripheral velocity, a plurality of article holding gates substantially uniformly spaced and secured to and located about the periphery of the article holder, each gate being adapted for holding a single article only, means to move the articles progressively toward the periphery of the rotatable holder with the aid of centrifugal force, means at one angular position of the holder for transferring the articles individually to an unloaded article-holding gate, means positioned adjacent to the holder periphery, and located along the arcuate path of the gates between the loading position and a selectable final discharge position, for sequentially exploring the gate-held articles to determine the characteristics of each and for providing controlling information indicative of a selected number of classes of substantially like-characteristic articles, means controlled by the controlling information for discharging the gate-held articles at a plurality of discharge points on the arcuate gate path in the region between the exploring means and the selectable final discharge point, and memory means controlled by the exploring means for determining the angular position for releasing the gate-held articles at the selected discharge points so that all articles having substantially like-charcteristics are discharged along a common trajectory.

l5. Sorting apparatus comprising a rotatable article holder, means to rotate the holder at a substantially constant rate, means to feed articles to the holder at a centrally located receiving area where the holder has low velocity relative to its peripheral velocity, a plurality of article holding gates pivotally secured to the holder and sequentially located about its periphery and uniformly spaced relative to each other, each gate being adapted for holding a single article only, means for moving articles from the central region to the peripheral gates when centrifugal force is developed due to holder rotation, means normally holding each gate closed during holder rotation, means positioned adjacent to the holder periphery and located along the arcuate path of the gates between the loading position and a final discharge position for sequentially exploring the gate-held articles to determine the characteristics of each and for providing controlling information indicative of a selected number of classes of substantially like-characteristic articles, means for inactivating the means for holding the gates closed and permitting the gate-held articles to be discharged at a plurality of discharge points on the article gate path in the region between the exploring means and the final discharge point, and magnetic memory means controlled by the exploring means for controlling the points where the gate-held articles are selectively discharged so that all articles having substantially like-characteristics are discharged along a common trajectory.

16. Sorting apparatus comprising an upturned dishshaped article holder, means to rotate the holder at a substantially constant rate, means to feed articles to the holder within its concavity at a centrally located receiving area where the velocity of rotational movement is low relative to its peripheral velocity, a plurality of article holding gates sequentially and uniformly spaced relative to each other and secured to the holder peripherally for outward movement relative thereto with each gate being adapted for holding a single article only to extend about the periphery of the article holder, means for transporting the articles from the central loading position of the holder to the gates with the aid of centrifugal force due to holder rotation, means for controlling the angular position at which the articles enter the gates, means for normally holding the gates closed, a gate release means for each gate to permit each gate to open when filled with an article, article exploring means positioned adjacent to the holder periphery and to the gates for exploring the gate-held articles one by one to determine with holder rotation, the characteristics for each held article, means for producing controlling signal pulse information indicative of which of a selected number of article classifications the instantly explored article is identified, means controlled by the article-characteristic signal pulse information for selectively releasing the gate opening means individually at selected times and at selected angular positions of the holder during rotation following article exploration so that with gate opening the article held moves away from the holder along a path tangential to the release point, and memory means controlled by the exploring means for determining each article discharge point so that all articles having substantially like-characteristics are discharged along a common trajectory.

17. Sorting apparatus comprising an upturned dishshaped article holder, means to rotate the holder at a substantially constant rate, means to feed articles to the holder at a centrally located receiving area where the velocity of rotational movement is low relative to its peripheral velocity, a plurality of substantially like-size uniformly spaced article holding gates sequentially arranged to extend about and to be secured to the periphery of the article holder, each gate being adapted for holding a single article only, means to move the articles from the feeding region to the gates with the aid of centrifugal force upon holder rotation, means to load the gates at one selected point angularly related to the holder rotation, means for normally holding the gates closed, a gate release means for permitting the opening of each gate due to centrifugal force acting upon the articles and removing the force to hold the article in the holder, article exploring means positioned adjacent to the holder periphery and to the gates for exploring the gate-held articles one by one in sequence to determine, with holder rotation, the characteristics of each means for producing controlling signal pulse information by the exploration with the in formation being indicative of which of a selected number of article classifications the instantly explored article is identified, means controlled by the article-characteristic information for selectively controlling the gate release means for permitting opening of the gates individually at selected angular positions of the holder during its ro tation so that concurrently with gate opening the holding force upon the article by the gate is removed and the article held moves away from the holder at substantially the peripheral velocity of the holder and along a path tangential to the release point, and memory means actuated by the signal pulse information developed by the exploring means for selectively determining each article discharge point so that all articles having substantially like-characteristics are discharged at a common point and substantially along a common trajectory.

18. In sorting apparatus, means to place articles from a group in an individual single-file array path, means to move the single-file arranged articles along the path against force tending continually and normally to remove the articles from the path, means for applying to each article in the path a holding force to counteract continually the removal force thereby to hold the articles in the arranged single file path, selection means for sequentially identifying the characteristics of each article in the singlefile arrangement and means at selected points along the path to remove the holding force under the control of the selection means thereby to permit the continuously acting removal force to remove the articles one by one along a path substantially tangential to the path of movement of the single-file arranged articles.

19. In sorting apparatus, means to move articles from a group into a single file relationship in which the articles traverse a circular path, means to move the articles in a substantially horizontal plane along the circular path against a force tending normally to remove the articles from the path in a direction substantially tangential to the circular path, means for applying a holding force of a magnitude sufficient to overcome the force tending to I remove the articles to each article as located on the circular path thereby to maintain the articles in the arranged single file relationship, means to explore each article substantially concurrently with its positioning on the circular path to determine the article characteristics, means at selected points along the circular path to remove the applied holding force to permit the continuously acting removal force to cause the articles to leave the circular path in a direction substantially tangential thereto and in substantially the plane of rotation, and means to allocate the point of force removal in accordance with the exploration of the articles to remove articles of like characteristics at like points.

References Cited in the file of this patent UNITED STATES PATENTS 1,970,107 Stebler Aug. 14, 1934 26 Hilton Nov. 29, 1938 Cox June 10, 1941 Troy May 25, 1943 Cox Aug, 3, 1943 Tyler Mar. 8, 1949 Bickley Dec. 25, 1951 Christiansen Jan. 8, 1952 Williams Feb. 24, 1953 Roop May 25, 1954 Broekhuysen et a1 Jan. 3, 1956 FOREIGN PATENTS Canada Jan. 16, 1951 

5. IN SORTING APPARATUS, A FRUSTO-CONICAL ARTICLE SUPPORT DISH, MEANS TO ROTATE THE DISH, A PLURALITY OF NORMALLY CLOSED ARTICLE HOLDING GATES UNIFORMLY DISTRIBUTED ABOUT AND SECURED TO THE DISH PERIPHERY, MEANS TO SUPPLY ARTICLES TO THE ROTATING SUPORT DISH WITHIN THE DISHED-OUT PORTION THEREOF IN A REGION WHERE ITS ROTATIONAL SPEED IS LOW RELATIVE TO ITS PERIPHERAL SPEED, MEANS TO TRANSFER ARTICLES FROM THE SUPPLY POSITION ONE BY ONE ALONG THE CONICAL DISH-WALL TO SEQUENTIALLY FILL THE GATES FROM A POINT INTERNALLY OF THE DISH PERIPHERY WITH THE FILLING OCCURRING AT ONE SELECTED POSITION DURING DISH ROTATION, MEANS TO EXPLORE THE ARTICLES SUBSEQUENT TO THEIR FILLING THE GATES AT A REGION ADJACENT TO ONE GATE POSITION THEREBY TO DETERMINE THE CHARACTERISTICS OF THE SEQUENCE OF HELD ARTICLES, AND MEANS TO RELEASE THE GATES INDIVIDUALLY DURING DISH ROTATION AT SELECTED POSITIONS BETWEEN EXPLORATION AND RELOADING TO SEGREGATE THE EXPLORED ARTICLES INTO LIKE CLASSIFICATIONS. 